I have bad sinus' at the best of times, and it gets worse during pregnancy for me. Like the whole time I'm congested and wake with sore throats etc.
I sleep on an angle the majority of the time.

My first pregnancy I got a cold, and was over not being able to breath through my nose o much that I downed a pack of mentos in about 2 minutes flat, just to clear my sinus with peppermint I was desperate